In this lesson, the students will supplement their knowledge of DNA structure by understanding and explaining how to use a technology that requires the analysis of DNA for real world applications. In this lesson the student will be able to explain what is gel electrophoresis and how is it used to separate pieces of DNA. The students will watch a quick video on gel electrophoresis and then create their own gel electrophoresis. The students will then use this gel electrophoresis to separate a sample of DNA.
RI LS1-2: Students demonstrate an understanding of the molecular basis of heredity by describing DNA structure and relating the DNA sequence to the genetic code. National Science Education Standard
(Content Standard A; 9-12): All students should develop abilities necessary to do scientific inquiry and understandings about scientific inquiry.
(Content Standard C; 9-12): All students should develop an understanding of molecular basis of heredity. Rhode Island Beginning Teacher Standards 2
Teachers create Learning Experiences that reflect an understanding of central concepts and tools of inquiry of the disciplines they teach. Teachers use a variety of explanations and multiple representations of concepts, including analogies, metaphors, and demonstrations and illustrations that help students develop conceptual understanding
Opportunities to Learn:
Depth of Knowledge
Webb 2 - Skill and Concept -explain the relationship between fact and term
Web 4 - Extended Thinking - application to the real world (create and analyze)
Prerequisite Knowledge
Advances in science that require the use of DNA
Plans for Differentiating Instruction
In addition to required questions for the mock interviews, the teams will have to create ten additional questions on their own. This will challenge students to think outside of the box and understand how the discovery of DNA impacts our lives today.
I will have a peer teacher (another teacher) to help me monitor the pair of students create a gel electrophoresis and provide support to students who are having a difficult time understanding gel electrophoresis.
By having the students watch a video, as well as, create a gel electrophoresis, I will incorporate tactile, auditory, and visual modalities of learning.
Accommodations and modifications
There are three students who have trouble concentrating on their work. In the interview teams, I will place these students with peers who are organized. These task-oriented students will serve as a model for the students who have trouble focusing.
There is a student who has illegible handwriting. I will allow this student to write any notes about the mock interview on his laptop.
Environmental factors
There are four students at every table. There are six tables. Every student is facing me.
There is space in the back, where the mock interviews will be conducted by the students.
Materials
I will need powerpoint slides that have questions about gel electrophoresis (see link in engagement part 1)
I will need a video that summarizes the use of gel electrophoresis to separate pieces of DNA (see engagement part 1)
Objectives:
After this lesson, the students will be able to:
Explain what is gel electrophoresis (artefact - watching a video about gel electrophoresis and creating a gel electrophoresis apparatus)
Explain how gel electrophoresis is used to separate pieces of DNA (artefact - watching a video about gel electrophoresis, creating a gel electrophoresis apparatus, administering an unknown DNA sample into a gel electrophoresis )
Instruction:
Opening:
1) As I take attendance, I will have the following written on the board: Off the top of your head, name a few advances in science that require the use of DNA. Write your answer in your notebook.
2) I will call on a few students to volunteer their answers.
3) During the discussion about the scientific advances, I will mention to the students that today and tomorrow they will learn and explain how to use a technology that requires the analysis of DNA for real world applications.
4) Today you will learn and be able to explain what is gel electrophoresis works as well as how and why is it used to analyze DNA?
Engagement
Part 1
1) Using the smart board, I will present the students with the following questions, without answers
What is gel electrophoresis? (It is an apparatus that uses electricity to separate pieces of DNA of different size)
What happens to DNA in gel electrophoresis? [pieces of DNA, in a sample, are separated by size (smaller molecules move faster and further in the agar)]
What direction does DNA move in gel electrophoresis? (DNA has a negative charge and moves toward the positive pole of the electrophoresis gel)
How do you compare an Unknown DNA sample to a known DNA sample? (A scientist can compare the size of an unknown DNA piece to the known size of a known DNA sample, and subsequently estimate the length the of the unknown piece of DNA)
2) The students will answer these questions in their notebooks by viewing a video on gel electrophoresis (video)
3) After the video, I will ask student volunteers to write the answer to each question on the whiteboard.
Part 2
1) I will tell the students that after they complete the following lab activity, I will expect each student to be able to explain how gel electrophoresis is used to separate pieces of DNA.
2) I will ask the students to pair up with a partner.
3) I will give each pair a sample of DNA in a test tube.
4) The pair will first create a gel electrophoresis apparatus. (The specific directions for creation and implementation of the gel electrophoresis will be attached in the near future). For now, I will have a general outline in creating and implementing the electrophoresis apparatus:
Add agar to salt water solution
Heat this solution in the microwave
Pour the gel into the mold and use a comb to create holes
Let the mold cool
Pour additional buffer solution into a large box
Place the mold into the buffer solution
5) The pair will then use the gel electrophoresis apparatus to evaluate the separation pattern of the DNA sample.
Using a pipette, add a loading buffer into the DNA sample
Using a pipette, add this DNA sample into one of the holes in the electrophoresis
Connect a power supply to the electrophoresis
Turn on the power supply (electricity)
Observe the movement of the different strands of DNA.
6) At the end of the lab activity, I will put a picture on the smart board of the expected separation pattern of the known DNA sample after gel electrophoresis. You can compare your results to the expected results.
7) During the creation of the electrophoresis apparatus and the separation of DNA, I will be moving around and asking students if they have any questions. I will ask each pair if they know where agar comes from (answer - it comes from the cell wall of specific seaweed). I will also ask the students in each pair if they know the role of the buffer solution (answer - it is a conductor of electricity).
8) I will evaluate each pair by seeing if they were able to produce the expected separation pattern with their DNA sample using gel electrophoresis.
Closure
I will ask a student volunteer if he/she can explain how gel electrophoresis works.
I will ask a student volunteer if he/she can explain how do pieces of DNA separate from other strands in gel electrophoresis.
I will ask the students to write a couple of paragraphs about the lab activity for homework. I will want each student to explain the purpose of gel electrophoresis, and how it separates pieces of DNA. They should also describe their findings (pattern of separation). If their results differed from the expected results, I will want the student to explain possible sources of error.
As I stated in the previous lessons, I will be collecting the student notebooks and evaluating the student's ability to answer all of the questions posed in the opening and engagement.
I will collect this homework at the beginning of the next period.
Assessment
Formative questions about how gel electrophoresis is used to separate pieces of DNA (video)
Formative questions about agar and buffer in gel electrophoresis (lab activity)
Evaluate whether the pair of students had separation patterns of DNA that were consistent with the expected results (lab activity) (Expected separation pattern will be uploaded in the near future)
Summary of lab activity findings and sources of error (homework) (rubric for homework will be uploaded in the near future)
Lesson Title: It's Electric
Context of Lesson:
In this lesson, the students will supplement their knowledge of DNA structure by understanding and explaining how to use a technology that requires the analysis of DNA for real world applications. In this lesson the student will be able to explain what is gel electrophoresis and how is it used to separate pieces of DNA. The students will watch a quick video on gel electrophoresis and then create their own gel electrophoresis. The students will then use this gel electrophoresis to separate a sample of DNA.Standard
RI LS1-2: Students demonstrate an understanding of the molecular basis of heredity by describing DNA structure and relating the DNA sequence to the genetic code.National Science Education Standard
(Content Standard A; 9-12): All students should develop abilities necessary to do scientific inquiry and understandings about scientific inquiry.
(Content Standard C; 9-12): All students should develop an understanding of molecular basis of heredity.
Rhode Island Beginning Teacher Standards 2
Teachers create Learning Experiences that reflect an understanding of central concepts and tools of inquiry of the disciplines they teach. Teachers use a variety of explanations and multiple representations of concepts, including analogies, metaphors, and demonstrations and illustrations that help students develop conceptual understanding
Opportunities to Learn:
Depth of Knowledge
Prerequisite Knowledge
Plans for Differentiating Instruction
Accommodations and modifications
Environmental factors
Materials
Objectives:
After this lesson, the students will be able to:Instruction:
Opening:
1) As I take attendance, I will have the following written on the board: Off the top of your head, name a few advances in science that require the use of DNA. Write your answer in your notebook.2) I will call on a few students to volunteer their answers.
3) During the discussion about the scientific advances, I will mention to the students that today and tomorrow they will learn and explain how to use a technology that requires the analysis of DNA for real world applications.
4) Today you will learn and be able to explain what is gel electrophoresis works as well as how and why is it used to analyze DNA?
Engagement
Part 1
1) Using the smart board, I will present the students with the following questions, without answers- What is gel electrophoresis? (It is an apparatus that uses electricity to separate pieces of DNA of different size)
- What happens to DNA in gel electrophoresis? [pieces of DNA, in a sample, are separated by size (smaller molecules move faster and further in the agar)]
- What direction does DNA move in gel electrophoresis? (DNA has a negative charge and moves toward the positive pole of the electrophoresis gel)
- How do you compare an Unknown DNA sample to a known DNA sample? (A scientist can compare the size of an unknown DNA piece to the known size of a known DNA sample, and subsequently estimate the length the of the unknown piece of DNA)
2) The students will answer these questions in their notebooks by viewing a video on gel electrophoresis (video)3) After the video, I will ask student volunteers to write the answer to each question on the whiteboard.
Part 2
1) I will tell the students that after they complete the following lab activity, I will expect each student to be able to explain how gel electrophoresis is used to separate pieces of DNA.
2) I will ask the students to pair up with a partner.
3) I will give each pair a sample of DNA in a test tube.
4) The pair will first create a gel electrophoresis apparatus. (The specific directions for creation and implementation of the gel electrophoresis will be attached in the near future). For now, I will have a general outline in creating and implementing the electrophoresis apparatus:
- Add agar to salt water solution
- Heat this solution in the microwave
- Pour the gel into the mold and use a comb to create holes
- Let the mold cool
- Pour additional buffer solution into a large box
- Place the mold into the buffer solution
5) The pair will then use the gel electrophoresis apparatus to evaluate the separation pattern of the DNA sample.- Using a pipette, add a loading buffer into the DNA sample
- Using a pipette, add this DNA sample into one of the holes in the electrophoresis
- Connect a power supply to the electrophoresis
- Turn on the power supply (electricity)
- Observe the movement of the different strands of DNA.
6) At the end of the lab activity, I will put a picture on the smart board of the expected separation pattern of the known DNA sample after gel electrophoresis. You can compare your results to the expected results.7) During the creation of the electrophoresis apparatus and the separation of DNA, I will be moving around and asking students if they have any questions. I will ask each pair if they know where agar comes from (answer - it comes from the cell wall of specific seaweed). I will also ask the students in each pair if they know the role of the buffer solution (answer - it is a conductor of electricity).
8) I will evaluate each pair by seeing if they were able to produce the expected separation pattern with their DNA sample using gel electrophoresis.
Closure
Assessment